Hosts Poland made an emphatic start to the men's European Lacrosse Challenge in Wrocław, beating Luxembourg 14-0 on the opening day of competition.
Tyler Kolodka scored five goals in the rout, as well as providing two assists.
That was the biggest win of the day, but Kolodka's five goals were eclipsed by Fran Vulić.
The Croatian marksman scored seven times - albeit across two games - as his side had a mixed day.
Croatia fell 11-6 to Slovakia in their first game, but later edged out Poland's under-21 side 7-6.
Matej Bodul scored the decisive goal in extra time and finished the day with a tournament-high eight points - three goals and five assists.
The Czech Republic beat Poland's under-21s 12-5 in the opening game of the tournament, although Poland had led 3-0.
The six-team round-robin stage continues tomorrow, with four more matches scheduled.
Saturday (July 24) is due to witness the final and playoffs for third and fifth places.
World Lacrosse, the global governing body, was today granted full International Olympic Committee (IOC) recognition by the IOC Session.